The aid group Doctors Without Borders is pulling out of Iraq, citing escalating violence and kidnappings.

The announcement comes as another aid organization, CARE International, awaits news on the fate of its director in Iraq, Margaret Hassan. Her unknown kidnappers have threatened to hand her over to wanted terrorist Abu Musab al-Zarqawi's network Thursday if British troops do not pull out of Iraq.

Meanwhile, U.S. and Iraqi troops continue to conduct air and ground assaults in the insurgent strongholds of Fallujah and Ramadi, west of Baghdad.

Analysts say a full-fledged military offensive to crush the insurgency in those cities is expected any day, now that the U.S. presidential election is over.

And police say at least three Iraqis were killed and several wounded in a car bombing outside city government offices in Dujail, south of Baghdad.